An investment advisory affiliate of Dallas-based Lincoln Property Co. has a contract to buy downtown Nashville's Fifth Third Center for about $89 million.

The affiliate could complete its acquisition of the 31-story, 490,281-square-foot office building at 424 Church St. this month, according to multiple people familiar with details of the sale.

If completed, the transaction would mark the biggest sale of an individual office building in the Nashville area this year. An overall softer office investment sales market was expected here this year after a record 2013 in which investors paid more than $100 million for individual buildings, including the Pinnacle at Symphony Place, Nashville City Center and, in Brentwood, AT&T Data Center.

"It provides further proof of the attractiveness and strength of the Nashville market and continued interest from investors who typically focus on larger markets for their investments," said Barry Smith, president of Nashville-based commercial real estate firm Eakin Partners, who's not involved with the Firth Third Center deal.

Locally, Lincoln has been active in the apartments market. Projects the developer plans include the 232-unit 909 Flats across from the Nashville Farmers' Market plus a 200- to 300-unit apartment building at Charlotte Avenue and 23rd Avenue North. Lincoln also manages 12 South Flats, The Lakes of Bellevue, Village Center Apartments and Waterford Place in Nashville and Ridgemont Park in Smyrna.

When Eastdil Secured of Atlanta listed Fifth Third Center in March for owner Amstar of Denver the building was 79 percent leased. Fifth Third Bank, Loews Hotels, Sony ATV Music, Deloitte, DSI Renal and Adams & Reese are among tenants.